So for about 2 weeks ive been having this burning/exhaust type smell coming into the cabin after about 3,500 RPM and up. Im pretty sure its not the clutch. Its not slipping. I thought it was one of my oil leaks burning, but i recently fixed them and its still there. I checked the coolant tank also, doesnt seem to be leaking.

Im about to go check my header, to see if it could be cracked up top? Might as well take a look. I check some other werid smell threads but havent found one like this.

Remember its only from 3,500rpm and up, and not only when boosting. I tried bringing the RPM's up without haveing the BPV close and the smell still came in around 40 mph.

2005 Mini Cooper S, 17% pulley, alta catback, alta intake, colder plugs.

 

My other idea was my cat could possibly be going, my only hint to that would be my high boost readings and possibly this smell? But would I be able to smell it from the cabin, and wouldnt I get a code?